Spain has deployed military to stop the migration after around 8,000 migrants arrived at the North African outpost, Cueta, which included at least 2,000 minors.

More than 4,000 of the arrived have already been sent back after the nation deployed troops, military trucks, and helicopters to stem the arrival.

The migrants had reached the enclave by swimming or walking at low tide from beaches in neighboring Morocco, and none of them have been hospitalized.

Videos posted on social media showed the stream of migrants - some wearing just beachwear but others clad in normal outdoor clothes - setting off from rocky beachheads.

"We are going to restore order to the city and its borders," Spanish Prime Minister Pedro Sanchez said during a televised address as he described the situation as a crisis.

Spanish Interior Minister Fernando Grande-Marlaksa told reporters Tuesday that Ceuta, a port city that borders Morocco and is separated from the rest of Spain by the Mediterranean Sea, "is as much Spain as Madrid, Seville or Barcelona."